In various applications it is desired to synchronize data on a number of incoming data lines which are asynchronous with respect to each other to a single system clock for further processing of the data signals. In such applications in which the data rates on the lines are substantially the same, the problem becomes one of tracking and aligning the phase of the incoming data on each line to coincide with that of the system clock. Known methods of accomplishing such phase alignment typically involve independent phase adjusting of the arriving data on each line. For example, in U.S. Pat. No. 3,459,893, issued to G. W. Thomas on Aug. 5, 1969, data on plural data lines are synchronized in phase by separately comparing synchronization pulses of the individual data streams to a system clock interval and using the results of the comparisons to individually adjust variable delay elements in each input stream to align the data.
Phase realignment techniques such as the above require apparatus dedicated on a per line basis and, thus, are costly to implement. A simpler and more economical technique is desirable.